Seminar: Multiparty testing preorders

Department of Computing, Faculty of Science, University of Buenos Aires

Abstract.Variants of the must testing approach have been successfully applied in
Service Oriented Computing for analysing the compliance between (contracts
exposed by) clients and servers or, more generally, between two peers. It
has however been argued that multiparty scenarios call for more permissive
notions of compliance, because partners usually do not have full
coordination capabilities.

We propose two new testing preorders, which are
obtained by restricting the set of potential observers. For the first
preorder, called uncoordinated, we allow only sets of parallel observers
that use different parts of the interface of a given service and have no
possibility of intercommunication. For the second preorder, that we call independent, we instead rely on parallel observers that perceive as
silent all the actions that are not in the interface of interest.

We have
that the uncoordinated preorder is coarser than the classical must testing
preorder and finer than the independent one. We also provide a
characterisation in terms of decorated traces for both preorders: the
uncoordinated preorder is defined in terms of must-sets and Mazurkiewicz
traces, while the distributed one is described in terms of classes of
filtered traces that only contain designated visible actions and must-sets.